Latching relay and electromagnetic actuator therefor



Oct. 12, 1965 w. F. JUPTNER 3,211,858

LATCHING RELAY AND ELECTROMAGNETIC ACTUATOR THEREFOR Filed June 21, 19632 Sheets-Sheet 1 m; 56 Z 220, 440 i I 60 INVENTOR. 246 WILLIAM F.JUPTNER T" "W W ATTORNEY ATTQRNEY /6a Q l 60a az fifl 30 INVENTOR.WILLlAM E JUPTNER FIG.8

Oct. 12, 1965 w. F. JUPTNER LATCHING RELAY AND ELECTROMAGNETIC ACTUATORTHEREFOR Filed June 21, 1963 United States Patent i 3,211,858 LATCHINGRELAY AND ELECTROMAGNETIC ACTUATQR THEREFOR William F. Juptner, LagunaBeach, Calif., assignor to Babcock Electronics Corporation, Monrovia,Calif., a corporation of California Filed June 21, 1963, Ser. No.289,637

9 Claims. (Cl. 200-93) The present invention relates generally tolatching relays and electromagnetic actuators therefor, and moreparticularly to such electromagnetic devices which are extremely smalland compact.

Although latching relays have been Well known in the electronic art formany years, prior devices of this kind have not been particularlydesirable for certain applications. Such prior devices have been soconstructed as to be relatively large and heavy. Accordingly, they havenot been useable in applications where size and weight of the electroniccomponents are important.

Today, many electronic components are used in equipment such as testprobes and capsules for use in exploring outer space. In view of thepower requirements for putting such a probe or capsule into orbit or inflight in outer space, the size and weight of a payload becomesexceedingly important. Accordingly, there has developed an acute needfor electronic components of minimium size and Weight.

It 'is an object of the present invention to teach the construction ofan electromagnetic actuator which is small and compact.

Another object of the present invention is to provide a small, compactelectromagnetic latching actuator which can be latched in either of twoextreme positions.

Another object of the present invention is to provide an electromagneticactuator as characterized above which can be magnetically latched ineither of its extreme positions.

A further object of the present invention is to provide an actuator ascharacterized'above which can be operated from one position to anothermerely by momentary energization of suitable electromagnetic means.

Another object of the present invention is to provide an electromagneticlatching actuator as characterized above wherein the electromagneticwinding for switching the device from one latched position to another iswound about the armature thereof.

A further object of the present invention is to provide anelectromagnetic latching actuator as characterized) above having anelectromagnetic winding which is tubular in shape providing an openingwherein the armature is movable between its said extreme positions.

A still further object of the present invention is to provide a latchingrelay having a small compact electromagnetic actuator as characterizedabove for controlling one or more pairs of electrical contacts.

An additional object of the present invention is to provide anelectromagnetic latching relay as characterized above wherein thecontacts comprise a stationary resilient contact to be engaged by amovable contactor such as to develop in said contactor a biasing forcewhich upon switching operation tends to move the armature such as toposition the contactor in separated relation with respect to thestationary contact.

A still further object of the present invention is to provide a latchingrelay as characterized above wherein the armature is pivotally attachedto a mounting member and the electromagnetic switching winding is woundabout the armature and mounting member therefor to provide a smallcompact relay.

An additional object of the present invention is to provide anelectromagnetic latching relay and actuator there- 3,211,858 PatentedOct. 12, 1965 for which is simple and inexpensive to manufacture, andwhich is rugged and dependable in operation.

The novel features which I consider characteristic of my invention areset forth with particularity in the appended claims. The device itself,however, both as to its organization and mode of operation, togetherwith additional objects and advantages thereof, will best be understoodfrom the following description of specific embodiments when read inconnection with the accompanying drawings, in which:

FIGURE 1 is a fragmentary perspective view of an electromagneticlatching relay according to the present invention;

FIGURE 2 is a side elevational view of the latching relay, the coverhaving been removed;

FIGURE 3 is a top plan view of the armature assembly for the latchingrelay;

FIGURE 4 is a fragmentary sectional view taken substantially along line44 of FIGURE 3;

FIGURE 5 is a side elevational view of the armature assembly takensubstantially along line 5-5 of FIG- URE 3;

FIGURE 6 is a perspective view of the armature-coil assembly;

FIGURE 7 is an exploded perspective view of the latching relay; and

FIGURE 8 is a fragmentary top plan view of the contact assembly of thesubject device.

Like reference characters indicate corresponding parts throughout theseveral views of the drawings.

Referring to FIGURE 1 of the drawings, the embodiment chosen forillustration of the present invention generally comprises a base 10wherein is positioned a cover 12 providing an enclosure 14 there within.Suitable terminal members 16a, 16b, 16c, 16d, 16e, 16f, 16g, 16h, 161and 16 depend from base 10 for purposes which will hereinafter bedescribed in detail. Cover 12 may be formed to firmly engage base 10, orit may be secured thereto as by welding, brazing, soldering, or the liketo hermetically seal enclosure 14.

Positioned within enclosure 14 is an electromagnetic actuator 18. Suchactuator comprises an armature assembly 20 as shown most clearly inFIGURES 3, 4 and 5 of the drawings. Assembly 20 comprises an armature 22pivotally mounted on a mounting member 24 formed of magneticallyimpermeable material.

Armature 22 is formed of magnetically permeable material and is providedwith a pair of opposite end portions 22a and 22b which are enlarged asat 22c and 22d, respectively, to provide armature pole pieces. As shownin FIGURE 5, the central or intermediate portion 22e of armature 22 isrelatively narrow in its vertical dimension but wide in its horizontaldimension as shown at 22] in FIGURE 3. Intermediate portion 22@ isformed with a pair of oppositely disposed cylindrical extensions 22g and22h which provide means for pivotally mounting armature 22 on mountingmember 24. Such extensions are coined during the forming of armature 22in a metal forming press provided for that purpose. That is, thearmature is formed in a pressing operation out of a suitable piece ofmagnetically permeable material. During such forming operationsufiicient material is permitted to remain at the central portion of thearmature to provide the cylindrical extensions 22g and 22h.

As will hereinafter become more apparent, the sides of the armature polepieces 22a and 22b may be tapered for proper engagement with stationarymagnetic pole pieces to be hereinafter described.

Mounting member 24 is provided with a fiat intermediate portion 24a anda pair of upstanding side flanges 24b and 240 which provide a generallyU-shaped cross section for the mounting member. Each of the flanges 24band 240 is formed with a generally square or rectangular cutout as at24d and 240, respectively, for receiving a mounting strap 26 as willhereinafter be explained.

Member 24 is formed with a pair of enlarged opposite end portions 24fand 24g which are offset downwardly from the intermediate portion 24a.

Intermediate portion 24a is formed with a centrallylocated throughopening 2411 for rotatably receiving the cylindrical extension 22h ofarmature 22 as shown in FIGURE 4. The periphery of such opening is bentupwardly as shown in said figure to provide an annular hearing surfacefor armature 22.

Mounting strap 26 is also provided with an opening 26a the peripheraledge of which is bent or offset to provide an annular bearing surfacefor the armature. Such opening 26a, as shown in FIGURES 3 and 4, receivethe cylindrical extension 22g of armature 22. Mounting strap 26 ispositioned within the cutouts 24d and 24e in the side flanges 24b and240 of mounting member 24 while armat-ure 22 is positioned as shown inthe drawings. Strap 22 is welded to the flanges of mounting member 24 toprovide a unitary structure comprising armature 22 and mounting member24.

Attached to each of the opposite ends of armature member 22 is a pair ofactuators 28. Each such pair of actuators comprises a pair of spacedactuator rods 30 welded to the armature in depending position as shownin the drawings. An insulating spheroid 32 is mounted on the lower endof each such depending actuator rod 30. As will hereinafter become moreapparent, such pairs of actuators 28 are operable to actuate electricalcontacts of the latching relay.

As shown most clearly in FIGURE 6 of the drawings, the armature assembly20 is provided with an electromagnetic winding to thereby effect anarmature-coil assembly 34. Assembly 34 is formed by positioning aboutarmature 22 and mounting member 24 a bobbin 36 formed of any suitablenonmagnetic material such as plastic or the like. Due to the enlargedopposite end portions 24 and 24g of mounting member 24, and due to theoffset nature of such end portions as above described, the bobbin 36 isformed in two halves 36a and 36b which are separated longitudinally asshown in FIGURE 6.

The bobbin members 36:: and 36b are brought into mating engagement fromopposite sides of the armature assembly 20 as indicated by the brokenline showing of bobbin member 36b in FIGURE 6. Such members may beprovided with suitable interlocking portions to insure proper alignmentthereof and to provide bobbin 36 with the proper central through opening360. Also, each bobbin member should be suitably formed so that thefinished tubular bobbin 36 is provided with flanges as shown at 36d, 36cand 36f.

As shown in FIGURE 6 of the drawings, bobbin 36 is generally tubular inconstruction, having either a circular cross section or a square orrectangular cross section, as desired. The generally rectangular crosssection has been found most desirable since it provides opening 360 withthe most desirable size and shape for accommodating the intermediateportion of the armature assembly 20. That is, by providing throughopening 360 with a generally rectangular cross section, the mountingmember 24 and armature 22 thereon are most easily accommodated.

A first electromagnetic winding 40 is provided on bobbin 36 betweenflanges 36d and 36e. A second such winding 42 is provided thereonbetween the flanges 36c and 36f. Such windings are intended to beenergized in opposite directions so as to effect magnetic polarizationof armature 22 in opposite directions as will hereinafter be explainedin detail. In the alternative, a single winding and means for reverselyenergizing it could be employed as will hereinafter become apparent.

A pair of frame members 44 and 46 are utilized in the device as magneticflux conducting members as will hereinafter appear. Such frame membersare identical in construction, and each com rises an elongated fluxconducting portion as shown at 44:: and 46a respectively. At each end ofsuch flux conducting portions, there is provided a stationary pole pieceas shown at 44b and 440 with respect to frame member 44, and at 4611 and460 with respect to member 46. The lower end portion of each suchstationary pole piece is bent outwardly to provide a flange to be weldedto the respective end portion of the mounting member 24.

Each of the frame members 44 and 46 is formed with a support, as shownat 44d with respect to member 44. The lower end portion of each supportis formed with a pair of depending fastening tabs as shown at 44c and 44The frame members 44 and 46 are formed in a metal forming press, and aremade of magnetically permeable material.

As will hereinafter become more apparent, the electromagnetic actuatorshown in the drawings and hereinabove described, provides a compactunitary structure. The relatively thin magnetic flux carrying portions44a and 46a of the frame members 44 and 46 permit the bulk of theenclosure 14 to be occupied by the coil structure itself. As such, alarge amount of magnetic flux is generated by the subject actuator ascompared to the size and weight thereof.

Frame members 44 and 46 are attached to a pair of permanent magnets 50and 52 which are positioned between each pair of opposed stationary polepieces. The magnet 50 is interposed between the stationary pole pieces44c and 46b at one end of the frames 44and 46 while the permanent magnet52 is interposed between the pole pieces 44b and 460 at the other endthereof. Such magnets are held in firm abutting relation with therespective pole pieces by mounting clips 54.

Each mounting clip 54 is generally U=shaped in con struction andcomprises a pair of side portions 54a and 54b, and in intermediateportion 540. Also, each clip 54 is provided with a supporting flange asshown at 54d in FIGURE 7. Whereas each permanent magnet is positionedbetween the pole faces of the opposed stationary pole pieces, the sideportions 54a and 54b of mounting clips 54 are positioned on the outsidethereof. That is, as shown in FIGURES 1, 2 and 7 of the drawings, theside portion 54a of clip 54 is positioned against the outer surface ofpole piece 44b while the side portion 54b is against the outer surfaceof the pole piece 460. The supporting flange 54d is positioned beneaththe permanent magnet to retain the same in elevated position withrespect to the armature 22. The side portions 54a and 54b are thenfastened to the respective stationary pole pieces as by spot welding,soldering or the like. Such arrangement firmly retains the permanentmagnets 50 and 52 in abutting relation with the respective pole pieces.

After the frame members and permanent magnets have been fastenedtogether to provide a unitary structure, the armature-coil assembly 34is inserted upwardly between the supports 44d and 46d of the framemembers 44 and 46 as shown more clearly in FIGURE 7. After this isaccomplished, the enlarged end portions 24 and 24g of mounting member 24are welded to the respective outwardly extending lower end portions ofthe stationary pole pieces. This provides a unitary structure of thearmature-coil assembly 34 and the frames 44 and 46. To hold the coilassembly in proper relation to the armature 22, the supports 44d and 46dmay be bent inwardly slightly.

As will hereinafter become more apparent, the permanent magnets 50 and52 are arranged in parallel circuit relation such that they cooperate inpolarizing the frame members 44 and 46. That is, such magnets areoriented such as to provide frame member 44 with a given magneticpolarity and to provide frame member 46 with the opposite magneticpolarity.

Mounted on top of base member is the contact assembly 56. Theaforementioned terminal members 16a, 16b, 16c, 16d, 167, 16g, 16h, 191and 16 are insulatedly mounted in base member 10 in such a manner as toprovide terminal posts within the enclosure 14. Each such terminal postis electrically and magnetically independent of all other terminal postsas provided by appropriate insulating means.

On each of the corner terminal posts, namely posts 16a, 16h, 16h and16i, there is provided a generally L shaped stationary contact 60. Oneend of each stationary contact 60 is reversely bent as at 60a to providemounting means for mechanically fastening. the contact to the respectiveterminal post. To insure good electrical contact between the contact andpost, a bead of solder as shown at 62 may be provided within the endportion 60a.

The free end 6011 of each stationary contact is bent as shown in thedrawings to provide a flat contact surface. Also, each stationarycontact 60. is formed of resilient material which exhibits goodelectrical conductivity.

Positioned between each pair of stationary contacts is an elongatedcontactor 64. The contactor 64 between the stationary contacts onmounting posts 16a and 16b is fastened to post 16g by means of agenerally L-shaped bracket 65. In like fashion, the contactor positionedbetween contacts on posts 16h and 161' is anchored to mounting post 16c.The L-shaped bracket 65 of each contactor may be firmly secured to therespective mounting post by a bead of solder 66. Each contactor 64 isformed with a relatively straight end portion 64b for good electricalcontact with the contact surfaces of the respective stationary contacts.

When the electromagnetic actuator 18 is attached to base 10, the pair ofinsulating spheroids 32 at each end of armature 22 are caused tostraddle the end portion 64b of the respective contactor 64 as shownmost clearly in FIGURES 3 and 8 of the drawings. To attach the actuator18 to base 10, the mounting tabs at the lower end of the support formedin each of the frame members 44 and 46 are inserted into suitablecutouts formed in the sides of base 10. Such tabs may be welded in suchpositions to firmly secure the electromagnetic actuator to base 10.

The ends of winding 42 are connected to terminal posts 16d and 16a asshown in FIGURE 7'. In like manner, the winding 40 has its opposite endsconnected to terminal posts 16f and 16 As will hereinafter become more.apparent, the windings 40 and 42 must be energized in oppositedirections. That is, if the direction of current flow through winding4!) is in a clockwise direction, the current flow through winding 42must be in a counterclockwise direction. This is necessary so thatenergization of windings 40 and 42 causes opposite magnetic polarizationof the armature 22.

After the electromagnetic actuator 18 has been properly mounted on base10 and all of the necessary electrical connections have been made, thecover 12 is positioned over the entire mechanism as shown in FIGURE 1.

The subject latching relay may be mounted in an appropriately formedsocket for receiving the aforedescribed terminal members.

The subject latching relay operates generally as follows.

With the permanent magnets 50 and 52 properly positioned as aboveexplained, the frame members 44 and 46 and their respective stationarypole pieces are caused to be oppositely magnetically polarized. As such,the armature 22 is free to pivot about its axis, as afforded bycylindrical extensions 22g and 22h, into engagement with either pair ofdiagonally positioned stationary pole pieces. That is, as shown inFIGURE 7, the armature can be positioned such that the pole piece 22b isin engagement with the stationary pole piece 44b of frame member 44.Such positioning of the armature causes the opposite armature pole piece22a to be moved into engagement with stationary pole piece 46b of framemember 46. As a result, there is provided a pair of parallel magneticcircuits for holding armature 22 in this position. A first circuit isprovided from the side of magnet 52 in engagement with stationary polepiece 44b through pole piece 44b, armature pole piece 22b, armature 22,armature pole piece 22a, stationary pole piece 46b, flux conductingportion 46a of frame member 46, and the stationary pole piece 460 to theother side of permanent magnet 52. V

The second magnetic circuit is completed from the side of permanentmagnet 50 in engagement with stationary pole piece 440 through magneticflux conducting portion 44a of frame 44, stationary pole piece 44b,armature pole piece 22b, armature 22, armature pole piece 22a andstationary pole piece 46b to the other side of permanent magnet 50.Thus, there is provided two parallel magnetic circuits which aid inmaintaining armature member 22 in one of its extreme positions.

With each pair of insulating spheroids 32 positioned on opposite sidesof the respective contactor 64, such positioning of armature 22 causesthe contactors to be in engagement with the stationary contacts onmounting posts 16b and 16h. That is, as shown in FIGURE 7, the armatureis positioned in its extreme clockwise position, thereby causing thecontactors 64 to be in their extreme clockwise positions completingelectrical circuits between terminals 16g and 16b, and between terminals16c and 16h.

It will be noted that armature 22 has been positioned as above describedmerely by the force of permanent magnets 50 and 52.

Thereafter, if the appropriate one of the windings 40 and 42 isenergized, the armature 22 becomes polarized so as to cause armaturepole piece 22b to be simultaneously repelled by stationary pole piece44b and attracted by pole piece 460 while armature pole piece 22a issimultaneously repelled by stationary pole piece 46b and attracted bypole piece 44c. That is, by energizing the appropriate one of windings40 and 42, the armature pole piece 22b is provided with the samemagnetic polarity as stationary pole piece 44b. At the same time, theopposite armature pole piece 22a is polarized opposite to armature polepiece 22b, but since stationary pole piece 46b is polarized opposite tostationary pole piece 44b, the armature pole piece 22a is now repelledby stationary pole piece 44b.

Such energization of the coil on armature 22 overcomes the heretoforeattractive force between armature 22 and the stationary pole pieces 44band 46b to cause the armature to pivot to its opposite position. i

As shown in FIGURE 8, the inherent resiliency of the stationary contactsengaged by the contactors 64 is utilized to aid the relay to itsopposite position. That is, with armature member 22 in its extremeclockwise position as above described, the stationary contacts 60 onmounting posts 16b and 16h are deformed sufliciently to develop abiasing force therein. As shown in broken lines in FIGURE 8, therespective stationary contacts are 'de formed sufficiently when thearmature is in one of its extreme positions to develop biasing forceswhich operate against the contactors 64. When the armature '22 is beingactuated to its opposite position by energization of one of the windings40 and 42, the biasing force developed in the respective contacts aidsthe movement of the contactors 64 toward the opposite stationarycontacts. Throughout such movement of armature 22, of course, theaformentioned reverse polarization thereof provides the major force formoving the armature to its opposite position. The polarization ofarmature 22 need only be momentary to cause the armature to be switchedto its opposite position.

With the armature 22 in its extreme counterclockwise position, thecontactors 64 are caused to' engage the stationary contacts on terminalpost's 16a and Mi. Thus the aforedescribed circuits are interrupted, andthe circuits including terminals 16a and 16g, and 160 and 16i arecompleted.

While the armature is in its counterclockwise position, a different pairof parallel magnetic circuits are operable for retaining the armature insuch position. Thereafter, upon energization of the other of thewindings 40 and 42, the latching relay is switched to its originalposition.

It should be particularly noted that the construction of the subjectlatching relay results in a very small compact structure which iscapable of performing work heretofore accomplished only by largerdevices. Mounting of the electromagnetic windings on the armatureassembly enables the electrical energy to be used more efficiently, andpermits the magnetic flux conducting frame to be smaller and morecompact.

Although the embodiment chosen for illustration of the present inventionis in the form of a double pole double throw switch, it is contemplatedwithin the scope of the present invention that substantially any desiredContact configuration may be employed.

Although I have shown and described certain specific embodiments of myinvention, I am fully aware that many modifications thereof arepossible. My invention, therefore, is not to be restricted exceptinsofar as is necessitated by the prior art and by the spirit of theappended ela im s.

I claim:

1. An electromagnetic actuator comprising in combination, a pair ofspaced magnetie frame members, mag iietic means inteposed between saidframe members to oppositely magnetically polarize said members, amounting member, an elongated armature pivotally mounted on saidmounting member between said frame members having opposite end portionsindividually engageable with said frame members to complete the magneticcircuit for said magnetic means, and electromagnetic means on saidarmature comprising a tubular bobbin about said mounting member andarmature and an electromagnetic winding on said bobbin energizable topolarize said armature to cause said end portions to be magneticallyrepelled from their respective frame members, whereby said armature iscaused to rotate to a different position.

2. An electromagnetic actuator comprising in combination, a mountingmember, a pair of magnetic frame members fixed to said mounting memberin spaced relation, a permanent magnet interposed between said framemembers to oppositely magnetically polarize said members, an elongatedarmature pivotally mounted on said mounting member having opposite endportions individually engageable with said frame members, andelectromagnetic means comprising a tubular bobbin positioned about saidmounting member and armature comprising a pair of electromagneticwindings individually energizable for opposite polarization of saidarmature to thereby control the rotative position of said armature withrespect to said frame members.

3. A latching relay comprising in combination, a mounting member, a pairof magnetic frame member fixed to said mounting member in spacedrelation, a permanent magnet interposed between said frame members tooppositely magnetically polarize said members, a magnetically permeableelongated armature pivotally mounted on said mounting member havingopposite end portions which are individually attracted to opposite onesof said frame members, a pair of electrical contacts for relativemovement by said armature between engaged and disengaged relativepositions, and electromagnetic means comprising a tubular bobbinpositioned about said mounting member and armature and a pair ofelectromagnetic windings on said bobbin individually energizable foropposite polarization of said armature to thereby control the positionto which said armature is magnetically attracted and the relativeposition of said contacts.

4. A latching relay comprising in combination, a mounting member, a pairof magnetic frame members fixed to said mounting member in spacedrelation, a permanent magnet interposed between said frame members tooppositely magnetically polarize said members, a magnetically permeablearmature pivotally mounted on said mounting member for movementalternatively to attracted positions with said frame members, a pair ofelectrical contacts for relative movement by said armature betweenengaged and disengaged relative positions, and electromagnetic meanscomprising at least one electromagnetic winding about said mountingmember and armature for opposite polarization of said armature tothereby control the position to which said armature is magneticallyattracted and the relative position of said contacts.

5. A latching relay comprising in combination, a magneticallyimpermeable mounting member, a pair of spaced magnetic frame members, :apermanent magnet interposed between said frame members to oppositelymagnetically polarize said members, a magnetically permeable armaturepivotally mounted on said mounting member having a portion to bealternatively attracted to opposite ones of said frame member, a pair ofelectrical contacts for relative movement by said armature betweenengaged and disengaged relative positions, and electromagnetic meanscomprising a tubular bobbin positioned about said mounting member andarmature and at least one electromagnetic winding on said bobbinenergizable for opposite polarization of said armature to therebycontrol the position to which said armature is magnetically attached andthe relative position of said contacts.

6. An electromagnetic actuator comprising in combination, and elongatedmagnetically impermeable mounting member having opposite end portions, apair of elongated magnetic frame members each of which is formed with apair of depending opposite end portions fixed to the opposite endportions of said mounting member to provide a unitary structuretherewith and at intermediate portion spaced from said mounting member,at least one permanent magnet interposed between said frame members tooppositely magnetically polarize them, a magnetically permeable armaturemovably mounted on said frame to be alternatively attracted to saidframe members, and electromagnetic means for reversely polarizing saidarmature to thereby control the position to which said armature isattracted comprising an electromagnetic winding about said mountingmember and armature thereon substantially filling the space between theopposite end portions of said frame members and between the mountingmember with armature thereon and said intermediate portions of saidframe members.

7. An electromagnetic actuator according to claim 6 wherein at least oneof said depending end portions of one of said frame members ispositioned in opposed spaced relation to one of said depending endportions of the other frame member, and said permanent magnet isinterposed therebetween to oppositely polarize said frame members.

8. An electromagnetic actuator according to claim 6 wherein said framemembers are aligned on said mounting member to cause each depending endportion of each frame member to be in opposed spaced relation to aseparate one of the depending end portions of the other frame member,and a permanent magnet is POSltlOned between each pair of opposed endportions to magnetically polarize said frame members.

9. An electromagnetic actuator according to cla1m 8 wherein saidarmature is pivotally mounted on said mounting member and is providedwith oppositely disposed pole portions for cooperation lndividually witha separate one of said pairs of opposed depending end portions of saidframes whereby one of said pole portions is attracted to an end portionof one 9f said frame members while the other pole portion is 9 10attracted to an end portion of the other of said frame 2,238,913 4/41Miller 200-93 X members. 2,252,761 8/41 Estes 200-93 2,816,190 12/57Peterson 20093 References Cied by the Examiner 3,030,469 4/62 L ich 20093 X UNITED STATES PATENTS 5 3,041,422 6/62 Greshel 200-93 X 16759197/28 Babcock 317 172 3,168,628 2/65 Okamoto et a1. 200104 X 2,051,4758/36 Grandstafi 200-93 BERNARD A. GILHEANY, Primary Examiner.

1. AN ELECTROMAGNETIC ACTUATOR COMPRISING IN COMBINATION, A PAIR OFSPACED MAGNETIC FRAME MEMBERS, MAGNETIC MEANS INTEPOSED BETWEEN SAIDFRAME MEMBERS TO OPPOSITELY MAGNETICALLY POLARIZE SAID MEMBERS, AMOUNTING MEMBER, AN ELONGATED ARMATURE PIVOTALLY MOUNTED ON SAID MOUTINGMEMBER BETWEEN SAID FRAME MEMBERS HAVING OPPOSITE END PORTIONSINDIVIDUALLY ENGAGEABLE WITH SAID FRAME MEMBERS TO COMPLETE THE MAGNETICCIRCUIT FOR SAID MAGNETIC MEANS, AND ELECTROMAGNETIC MEANS ON SAIDARMATURE COMPRISING A TUBULAR BOBBIN ABOUT SAID MOUNTING MEMBER ANDARMATURE AND AN ELECTROMAGNETIC WIND-